Lublin, maja 2022 r.

Lublin, 22 - 26 maja 2022 r.

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XX Krajowa Konferencja Nadprzewodnictwa

„Nowe fazy, koncepcje i zastosowania”

„New phases, concepts and advances”

Lublin, 22–26 V 2022

Komitet Naukowy Scientific Committee

Marta Z. Cieplak (IF PAN Warszawa), Roman Micnas (UAM Pozna ´n),

Krzysztof Rogacki (INTiBS PAN Wrocław), Wojciech Sadowski (PG Gda ´nsk),

Józef Spałek (UJ Kraków), Andrzej Szytuła (UJ Kraków), Andrzej ´Slebarski (U ´S Katowice), Karol I. Wysoki ´nski (UMCS Lublin)

Komitet Organizacyjny Organising Committee

Bartłomiej Baran (UMCS Lublin), Hadi Cheraghi (UMCS Lublin),

Tadeusz Doma ´nski (UMCS Lublin) – Chairman Szczepan Głodzik (J. Stefan Institute Ljubljana), El˙zbieta Jartych (Politechnika Lubelska),

Aksel Kobiałka (University of Basel), Nicholas Sedlmayr (UMCS Lublin), Karol I. Wysoki ´nski (UMCS Lublin)

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Szanowni Pa´nstwo,

Niecały rok po odkryciu w 1986 roku nadprzewodników wysokotemperatu- rowych odbyło sie, w Warszawie pierwsze ogólnopolskie spotkanie badaczy zjawiska nadprzewodnictwa i nadprzewodza,cych materiałów. Współprzewodni- cza,cymi jednodniowego spotkania byli Dyrektorzy dwu Instytutów Akademii Nauk, profesorowie Jan Klamut (INTiBS we Wrocławiu) i Henryk Szymczak (IF PAN w Warszawie). Po 35 latach spotykamy sie, ju˙z po raz dwudziesty w ramach tego cyklu. Dotychczas konferencje odbywały sie, na ´srednio co 22 miesia,ce. Grupa lubelska organizuje ja, po raz czwarty, ale pierwszy raz miejscem spotkania jest miasto Lublin. Mamy nadzieje,, ˙ze czterodniowa kon- ferencja be,dzie dobra, okazja, do wymiany pogla,dów na temat tego wa˙znego zjawiska oraz przyczyni sie, do odnowienia kontaktów naukowych osłabionych przez pandemie, COVID-19 i nawia,zania nowych form współpracy.

Zyczymy Pa´nstwu miłego pobytu i owocnych dyskusji naukowych, ˙ Organizatorzy

https://sites.google.com/view/kkn2022pl

Sponsorzy

Sponsors

• Jego Magnificencja Rektor Uniwersytetu M. Curie-Skłodowskiej, prof. dr hab. Radosław Dobrowolski

• Instytut Fizyki Uniwersytetu M. Curie-Skłodowskiej

• Oddział Lubelski Polskiego Towarzystwa Fizycznego

Lista konferencji nadprzewodnictwa / List of conferences on superconductivity 1. I Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego,

Warszawa, kwiecie´n 1987 r.

2. II Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego, Kraków, 28-29 stycznia 1988 r.

3. III Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego, Wrocław, 21-22 pa´zdziernika 1991 r.

(organizator: Instytut Niskich Temperatur i Bada´n Strukturalnych PAN we Wrocławiu) 4. IV Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego,

Pozna´n, 1993 r.

(organizatorzy: Instytut Fizyki Molekularnej PAN i Uniwersytet im. Adama Mickiewicza w Poznaniu)

5. V Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego, Kazimierz Dolny, 22-25 stycznia 1995 r.

(organizator: Instytut Fizyki Uniwersytetu Marii Curie-Skłodowskiej w Lublinie) 6. VI Mie,dzynarodowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego,

Zakopane, 23-28 wrze´snia 1996 r.

(organizatorzy: Instytut Fizyki Uniwersytetu Jagiello´nskiego i Akademia Górniczo-Hutnicza w Krakowie)

7. VII Krajowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego, Mie,dzyzdroje, 01-03 wrze´snia 1997 r.

(organizator: Instytut Fizyki Politechniki Szczeci´nskiej)

8. VIII Krajowe Sympozjum Nadprzewodnictwa Wysokotemperaturowego, Gda´nsk-Sobieszowo, 07-10 wrze´snia 1999 r.

(organizator: Wydział Fizyki Technicznej i Matematyki Stosowanej Politechniki Gda´nskiej) 9. IX Szkoła Nadprzewodnictwa Wysokotemperaturowego,

Krynica-Czarny Potok, 10-14 czerwca 2001 r.

(organizatorzy: Instytut Fizyki Uniwersytetu Jagiello´nskiego i Akademia Górniczo-Hutnicza w Krakowie)

10. X Krajowa Szkoła Nadprzewodnictwa

„Nadprzewodnictwo wysokotemperaturowe i inne zjawiska w perowskitach”, Warszawa, 06-10 czerwca 2004 r.

(organizator: Krajowa Sie´c Naukowa „Silnie skorelowane fermiony

- od nadprzewodnictwa do kolosalnego magnetooporu”, Instytut Fizyki PAN w Warszawie) 11. XI Krajowa Szkoła Nadprzewodnictwa

„Zjawiska kolektywne i ich współzawodnictwo”, Kazimierz Dolny, 25-29 wrze´snia 2005 r.

(organizator: Krajowa Sie´c Naukowa „Silnie skorelowane fermiony - od nadprzewodnictwa do kolosalnego magnetooporu”,

Instytut Fizyki Uniwersytetu M. Curie-Skłodowskiej w Lublinie)

12. XII Krajowa Szkoła Nadprzewodnictwa

„Układy skorelowanych elektronów wczoraj i dzi´s”, Ustro´n, 14-18 wrze´snia 2006 r.

(organizator: Instytut Fizyki Uniwersytetu Jagiello´nskiego w Krakowie) 13. XIII Krajowa Szkoła Nadprzewodnictwa

„Nadprzewodnictwo, uporza,dkowanie spinowe i ładunkowe”, La,dek Zdrój, 06-10 pa´zdziernika 2007 r.

(organizator: Instytut Niskich Temperatur i Bada´n Strukturalnych PAN we Wrocławiu) 14. XIV Krajowa Szkoła Nadprzewodnictwa

„Nadprzewodnictwo i niejednorodne układy skondensowane”, Ostrów Wielkopolski, 13-17 pa´zdziernika 2009 r.

(organizatorzy: Instytut Fizyki Molekularnej PAN, Uniwersytet A. Mickiewicza w Poznaniu) 15. XV Krajowa Szkoła Nadprzewodnictwa

„Sto lat nadprzewodnictwa”,

Kazimierz Dolny, 09-13 pa´zdziernika 2011 r.

(organizator: Instytut Fizyki Uniwersytetu M. Curie-Skłodowskiej w Lublinie) 16. XVI Krajowa Konferencja Nadprzewodnictwa

„Niekonwencjonalne nadprzewodnictwo i układy silnie skorelowane”, Zakopane, 07-12 pa´zdziernika 2013 r.

(organizatorzy: Instytut Fizyki Uniwersytetu Jagiello´nskiego i Akademia Górniczo-Hutnicza w Krakowie)

17. XVII Krajowa Konferencja Nadprzewodnictwa

„Nadprzewodnictwo i inne stany emergentne w układach z silnie skorelowanymi elektronami”, Karpacz, 25-30 pa´zdziernika 2015 r.

(organizator: Instytut Niskich Temperatur i Bada´n Strukturalnych PAN we Wrocławiu) 18. XVIII Krajowa Konferencja Nadprzewodnictwa

Krynica Morska, 08-13 pa´zdziernika 2017 r.

(organizator: Wydział Fizyki Technicznej i Matematyki Stosowanej Politechniki Gda´nskiej) 19. XIX Krajowa Konferencja Nadprzewodnictwa

„Niekonwencjonalne nadprzewodnictwo i silnie skorelowane układy elektronowe”, Bronisławów, 06-11 pa´zdziernika 2019 r.

(organizator: Instytut Fizyki PAN w Warszawie) 20. XX Krajowa Konferencja Nadprzewodnictwa

„Nowe fazy, koncepcje i zastosowania”, Lublin, 22-26 maja 2022 r.

(organizator: Instytut Fizyki Uniwersytetu M. Curie-Skłodowskiej w Lublinie)

Professor Roman Micnas (1947-2022)

With deep sorrow we learned that Prof. Roman Micnas, a distinguished Polish physicist, passed away on 13 January 2022. He was born in Nowice on November 4th, 1947. He graduated with MSc from Adam Mickiewicz University (AMU) in 1970, where he also received PhD degree in 1978, Habilitation (Dr hab.) degree in 1988, and became a Professor of physics in 1990. In the Faculty of Physics of AMU he was the head of Solid State Theory Division in years 1998-2018.

He published a number of important contributions to the theory of condensed matter physics. In his works he covered mainly the theory of superconductivity, strongly correlated materials, magnetism, phase tran- sitions, and ultracold atoms on optical lattices. His main achievement consists in development of the theory of superconductivity with local electron pairing. In this field he published a number of seminal works, including the highly cited review article: Rev. Mod. Phys. 62, 113-173 (1990), with Julius Ranninger and Stanisław Robaszkiewicz as the co-authors. He published over 140 articles in various fields of physics, inter alia together with Karl Alex Müller. Roman Micnas gave over 60 invited talks at international conferences and he promoted six doctoral students.

Professor Micnas paid long term research visits to the University of Linköping, Sweden (collaboration with K. A. Chao); ICTP Trieste, Italy; University of Grenoble; the Institute Laue-Langevin, Grenoble;

CNRS Grenoble, France (collaboration with J. Ranninger). In total, as a visiting professor he stayed in 15 scientific institutions in Sweden, Brazil, France, Italy, Germany, Switzerland and USA.

For his development of theory of superconductivity with local electron pairing he was awarded, together with Stanisław Robaszkiewicz, the Marie Skłodowska-Curie Scientific Prize of the Polish Academy of Sciences (PAS) in 1989. In 1994 he became Corresponding Member of PAS, and in 2016 - Ordinary Member. He served a number of important functions in PAS, among others he was a member of Com- mittee for Physics of PAS, and since 2015 a Dean of Division III of Exact Sciences and Earth Sciences of PAS. He was a member of several scientific societies: Polish Physical Society, European Physical Soci- ety, American Physical Society and American Association for Advancement of Science. He coorganized 35 national and international conferences, among others the cycle of the European Conferences „Physics of Magnetism”, which he organized and co-chaired since 1993.

Professor Roman Micnas took very active part in the whole series of National Conferences on Supercon- ductivity both as a member of the Scientific Committees and as a lecturer. He actively contributed to the success of these Conferences and the superconductivity research in Poland.

We shall remember him as an excellent scientist and a very friendly Member of our Community.

Tadeusz Doma´nski^a, Tomasz Kostyrko^b, Andrzej M. Ole´s^c, and Karol I. Wysoki´nski^a

aFaculty of Mathematics, Physics and Computer Science, M. Curie-Skłodowska University, Lublin

bFaculty of Physics, Adam Mickiewicz University, Pozna´n

cFaculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Kraków

SCIENTIFIC PROGRAMME

Sunday (22 May 2022) from 15:00 Registration

17:00 - 19.00 Sightseeing tour of the Castle and Old Town of Lublin 19:00 - 20.00 Supper

20:00 - 20.15 Tadeusz Doma´nski [M. Curie-Skłodowska University, Lublin]

Conference opening

20:15 - 21:00 Wiesław Ignacy Gruszecki [M. Curie-Skłodowska University, Lublin] . . . W.I Dlaczego warto zadba´c aby ˙zółta plamka w naszym oku była naprawde, ˙zółta?

Monday (23 May 2022) Chair Karol I. Wysoki´nski

09:00 - 09.45 Józef Spałek [Jagiellonian University, Cracow] . . . W.01 A brief perspective in high temperature superconductivity

09:45 - 10:15 Artur Malinowski [Polish Academy of Sciences, Warsaw] . . . W.02 Pseudogap in underdoped cuprate seen in longitudinal magnetoresistance

10:15 - 10:45 Coffee break

Chair Andrzej M. Ole´s

10:45 - 11:15 Wojciech Tabi´s [AGH University of Science and Technology, Cracow] . . . W.03 Cuprates - the perspective of electronic transport

11:15 - 11:45 Tomasz Cichorek [Polish Academy of Sciences, Wrocław] . . . W.04 Two-band superconductivity in electron-irradiated PrOs₄Sb₁₂and CeCu₂Si₂

studied by local magnetization measurements

11:45 - 12:15 Andrzej Szewczyk [Institute of Physics, Polish Academy of Sciences, Warsaw] . . . W.05 Magnetic phase transition in TbAl₃(BO₃)₄below 700 mK - quantum and classical features 12:15 - 12:45 Karolina Górnicka [Gda´nsk University of Technology, Gda´nsk] . . . W.06

Superconductivity in Os-based Laves compounds 13:00 - 15:00 Lunch

Chair Krzysztof Rogacki

15:00 - 15:30 Andrzej M. Ole´s [Jagiellonian University, Cracow] . . . W.07 Hubbard subbands in the infinite-layer nickelate

15:30 - 16:00 Jacek Herbrych [Wrocław University of Science and Technology, Wrocław] . . . W.08 Hund excitations in orbital-selective Mott insulators

16:00 - 16:30 Marcin M. Wysoki´nski [MagTop, Warsaw] . . . W.09 Non-Abelian Berry phase induced entanglement between qubits in QED cavity

16:30 - 17:00 Coffee break

Chair Roman Pu´zniak

17:00 - 17:30 Bartłomiej Wiendlocha [AGH University of Science and Technology, Cracow] . . . W.10 Strong-coupling superconductivity of SrIr₂and SrRh₂: Phonon engineering of metallic Ir and Rh 17:30 - 18:00 Artur Durajski [Cze,stochowa University of Technology, Cze,stochowa] . . . W.11

Ternary superhydrides: in search of low-pressure high-temperature superconductor

18:00 - 18:30 Tomasz Kostyrko [A. Mickiewicz University, Pozna´n] . . . W.12 Theory of superconductivity with local electron pairing: history and perspectives

18:30 - 18:50 Andrzej Szytuła [Jagiellonian University, Cracow] . . . W.13 Chwila wspomnie´n po 36 latach

19:00-20:00 Supper 20:00-21:00 Poster session

Tuesday (24 May 2022) Chair Tomasz Dietl

09:00 - 09.45 Marta Z. Cieplak [Institute of Physics, Polish Academy of Sciences, Warsaw] . . . W.14 Interplay of various order parameters and disorder in iron chalcogenides

09:45 - 10:15 Tomasz Klimczuk [Gda´nsk University of Technology, Gda´nsk] . . . W.15 Superconductivity in the Heusler-type intermetallic compounds

10:15 - 10:45 Coffee break

Chair Andrzej ´Slebarski

10:45 - 11:15 Andrzej Wi´sniewski [Institute of Physics, Polish Academy of Sciences, Warsaw] . . . W.16 Properties of (Nb,Pb,In)/NbP - superconductor Weyl semimetal junctions

11:15 - 11:45 Grzegorz Jung [Ben Gurion Univ. Negev, Israel & Institute of Physics PAS, Warsaw] . . . W.17 Chiral molecule mediated proximity effect

11:45 - 12:15 Paweł Starowicz [Jagiellonian University, Cracow] . . . W.18 Electronic structure of the heavy fermion superconductor Ce₃PdI₁₁

with two inequivalent crystallographic positions of Ce atoms

12:15 - 12:45 Damian Rybicki [AGH University of Science and Technology, Cracow] . . . W.19 Badanie ˙zelazowo-arsenowych nadprzewodników wysokotemperaturowych

z wykorzystaniem promieniowania synchrotronowego 13:00 - 15:00 Lunch

Chair Andrzej Szytuła

15:00 - 15:30 Paweł Jakubczyk [University of Warsaw, Warsaw] . . . W.20 Stability of the Fulde-Ferrel-Larkin-Ovchinnikov phases in Fermi mixtures:

role of the Lifshitz point

15:30 - 16:00 Maciej Fidrysiak [Jagiellonian University, Cracow] . . . W.21 Spin and charge quantum excitations in high Tc cuprates

16:00 - 16:30 Tomasz Polak [A. Mickiewicz University, Pozna´n] . . . W.22 Coexistence of two kinds of superfluidity

16:30 - 17:00 Coffee break

Chair Marta Z. Cieplak

17:00 - 17:20 Mateusz A. Gala [AGH University of Science and Technology, Cracow] . . . W.23 The interplay between lattice distortion and superconductivity in cuprate superconductors 17:20 - 17:40 Gabriel Kuderowicz [AGH University of Science and Technology, Cracow] . . . W.24

Origin of the phonon soft mode in Heusler compound LiPd₂Ge

17:40 - 18:00 Marlena Dziurawiec [Wrocław University of Science and Technology, Wrocław] . . . W.25 Equilibrium and nonequilibrium criticality in the one-dimensional XY model

with long-range interactions

18:00 - 18:20 Bartosz Krajewski [Wrocław University of Science and Technology, Wrocław] . . . W.26 Phenomenology of spectral functions in disordered spin chains at finite temperature

18:20 - 18:40 Hadi Cheraghi [M. Curie-Skłodowska University, Lublin] . . . W.27 Floquet dynamical phase transitions

19:00-20:00 Supper 20:00-21:00 Poster session

Wednesday (25 May 2022) Chair Wojciech Sadowski

09:00 - 09.45 Tomasz Dietl [MagTop, Warsaw & Tohoku University, Sendai (Japan)] . . . W.28 Exchange interactions in magnetically doped semiconductors

09:45 - 10:15 Maciej M. Ma´ska [Wrocław University of Science and Technology, Wrocław] . . . W.29 Topological superconductivity driven by self-organized spin structures

10:15 - 10:45 Coffee break

Chair Andrzej Wi´sniewski

10:45 - 11:15 Nicholas Sedlmayr [M. Curie-Skłodowska University, Lublin] . . . W.30 Instability of Majorana states in Shiba chains due to leakage into a topological substrate

11:15 - 11:45 Marcin Mierzejewski [Wrocław University of Science and Technology, Wrocław] . . . W.31 Interaction-induced Majorana edge states in multiorbital chains

11:45 - 12:15 Mircea Trif [MagTop, Warsaw] . . . W.32 Yu-Shiba-Rusinov qubit

12:15 - 12:45 Kacper Wrze´sniewski [A. Mickiewicz University, Pozna´n] . . . W.33 Dynamical quantum phase transition in a mesoscopic superconducting system

13:00 - 15:00 Lunch

Chair Marcin Mierzejewski

15:00 - 15:30 Andrzej Ptok [Institute of Nuclear Physics, Polish Academy of Sciences, Cracow] . . . W.34 Ab initio study of chiral phonons

15:30 - 16:00 Krzysztof Wójcik [M. Curie-Skłodowska University, Lublin] . . . W.35 Interplay of strong correlations and superconductivity in double quantum dots

16:00 - 16:30 Jan Bara´nski [Military University of Aviation, De,blin] . . . W.36 Quench dynamics of Fano-like resonances in double quantum dot systems

16:30 - 17:00 Coffee break

Chair Radosław Szcze,´sniak

17:00 - 17:30 Aksel Kobiałka [University of Basel, Switzerland] . . . W.37 Sublattice extension of the Rashba nanowire model

17:30 - 17:50 Małgorzata Strzałka [Wrocław University of Science and Technology, Wrocław] . . . W.38 Nontrivial spin textures in superconducting two-dimensional materials

17:50 - 18:10 Surajit Basak [Institute of Nuclear Physics, Polish Academy of Sciences, Cracow] . . . W.39 Shiba states in systems with density of states singularities

18:10 - 18:30 Grzegorz Górski [University of Rzeszów, Rzeszów] . . . W.40 Magnetic field effect on transport properties of double quantum dot coupled to Majorana wire 18:30 - 18:50 Maksymilian Kliczkowski [Wrocław University of Science and Technology, Wrocław] . . . . W.41

Artificial neural network solution to problems of many body correlated systems 20:00-21:00 Conference dinner

Thursday (26 May 2022) Chair Józef Spałek

09:00 - 09.45 Dariusz Kaczorowski [Polish Academy of Sciences, Wrocław] . . . W.42 Mixed singlet-septet Cooper pairing in half-Heusler superconductors

09:45 - 10:15 Roman Pu´zniak [Polish Academy of Sciences, Warsaw] . . . W.43 Enhancement of superconducting state properties and crystallinity degradation as a result of chemical substitutions, under pressure, and after hydrogenation in Fe-Te-Se single crystals 10:15 - 10:45 Coffee break

Chair Maciej M. Ma´ska

10:45 - 11:15 Krzysztof Rogacki [Polish Academy of Sciences, Wrocław] . . . W.44 Superconductivity by dislocation bundles in SrTiO₃

11:15 - 11:45 Kamil Kolincio [Gda´nsk University of Technology, Gda´nsk] . . . W.45 Spin chirality produced by thermal spin fluctuations

11:45 - 12:15 Sylwia Gutowska [AGH University of Science and Technology, Cracow] . . . W.46 Anisotropy of superconducting gap of Pb-Bi alloy

12:15 - 12:45 Ryszard Radwa´nski [Center of Solid State Physics & Pedagogical University, Cracow] . . . . W.47 Quantum Atomistic Solid State Theory: CeRh₂Si₂, K₂CoF₄, LaCoO₃, Sr₂VO₄, Ba₂IrO₄, Sr₂RuO₄ 12:45 - 13:00 Closing remarks

13:00 - 15:00 Lunch

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POSTER SESSION

P-01 I. Abaloszewa, M.Z. Cieplak, A. Abaloszew, L.Y. Zhu, C.-L. Chien Thermomagnetic instabilities in Nb films

P-02 S. Altanany, I. Zajcewa, M.Z. Cieplak,

Berezinski-Kosterlitz-Thouless transition in ultrathin niobium films P-03 B. Baran, R. Taranko, T. Doma´nski,

Subgap dynamics of double quantum dot system

P-04 E.E. Oyeka, M.J. Winiarski, A. Błachowski, K.M. Taddei, T.T. Tran,

57Fe Mössbauer study of a potential skyrmion host Fe(IO3)3

P-05 B. Camargo, A. Alaferdov, B. Kerdi, W. Escoffier,

Graphite’s magnetoresistance anomaly outside the quantum limit P-06 V. Chabanenko, A. Nabiałek, R. Pu´zniak,

Avalanche dynamics of magnetic flux in the Nb-Ti superconducting tube P-07 E.A. Drzazga-Szcze¸´sniak, A.Z. Kaczmarek,

The selected superconducting properties of electron- and hole-doped graphene P-08 P. Gierłowski, B. Cury Camargo, I. Abaloszewa, A. Abaloszew,

M. Jaworski, K. Cho, R. Prozorov, M. Ko´nczykowski,

Superconducting properties of electron-beam irradiatedBa1−xKxAs2F2

P-09 M. Hendzel, M. Fidrysiak, J. Spałek,

Mottness in many-particle reinterpretation of chemical bonding P-10 A.Z. Kaczmarek, E.A. Drzazga-Szcze¸´sniak,

The superconducting energy gap in the hole-doped graphene beyond the Migdal’s theory P-11 K. Kome,dera, I. Biało, W. Tabi´s, D. Tolj, N. Bariši´c,

Mössbauer spectroscopy study of K₂FeCu₃S₄murunskite P-12 S. Królak, K. Górnicka, M.J. Winiarski, T. Klimczuk,

Possible weak localization in a layered oxypnictide La₃Cu₄P₄O₂ P-13 A. Krzywicka,

Pairing mechanism at finite temperatures in bosonic systems P-14 R.J. Radwa´nski, D.M. Nałe,cz, Z. Ropka,

Charge, spin-orbit and crystal-field electronic states in CeRh₂Si₂

P-15 P. Sobota, R. Idczak, A.P. Pikul,

Superconductivity in (NbTa)_0.67(MoHfW)_0.33high entropy alloy P-16 K. Pryga, B. Wiendlocha,

Electronic structure and superconductivity in Co-Ni-Cu-Rh-Ir-Zr2 high entropy alloy P-17 P. Sobota, R. Idczak, T. Pikula, D. Gnida, A.P. Pikul,

Superconductivity in High Entropy Alloys with Th P-18 M. Rosmus, N. Olszowska, Z. Bukowski, P. Starowicz,

Electronic Structure and Dirac Cone Dispersion in Cobalt Doped CaFe₂As₂ P-19 D. Szcze,´sniak,

Quasiparticle tunneling in Josephson junctions via in-gap states

P-20 H. ´Swia,tek, L.S. Litzbarski, M.J. Winiarski, I. Oshchapovskyy, T. Klimczuk, Crystal structure and superconductivity in ternary Y₂Pd_1.25Ge_2.75intermetallic P-21 J. Wronowicz, M. Mierzejewski, J. Hebrych,

Level statistics and integrability breaking in chains with long-rang interactions P-22 T. Zajarniuk, A. Szewczyk, M.U. Gutowska, W. Szuszkiewicz, E. Lhotel,

H. Szymczak, R. Pu´zniak, A. Prokhorov,

The intriguing nature of phase transition in DyAl₃(BO₃)₄aluminoborate P-23 I. Zajcewa, M. Chrobak, M.Z. Cieplak,

Coulomb blockade effect in highly underdoped LSCO thin films

LECTURES

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XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Opening

lecture W-I

Dlaczego warto zadba´c aby ˙zółta plamka w naszym oku była naprawde, ˙zółta?

Wiesław Gruszecki

Katedra Biofizyki, Uniwersytet Marii Curie-Skłodowskiej w Lublinie

Oko - narza,d wzroku człowieka jest organem dostarczaja,cym najwie,ksza, cze,´s´c informacji o otaczaja,cym nas ´swiecie, umo˙zliwiaja,c efektywne, bezpieczne i twórcze funkcjonowanie. Ze wzgle,du na fakt, i˙z oko ludzkie wyposa˙zone jest w miliony fotoreporterów wra˙zliwych na promieniowanie o ró˙znej dłu- go´sci fali, nasze widzenie jest nie tylko precyzyjne ale równie˙z umo˙zliwiaja,ce rozró˙znianie tysie,cy barw. Funkcjonowanie oka ludzkiego w ekstremalnie szerokim zakresie intensywno´sci ´swiatła wymaga poła,czenia wysokiej czuło´sci fotoreceptorów z ich foto-stabilno´scia,. Okazuje sie,, ˙ze te przeciwstawne wymagania sa, niezwykle trudne do pogodzenia. W tym celu w ludzkim narza,dzie wzroku funkcjonuja, mechanizmy regulacyjne kontroluja,ce intensywno´s´c strumienia fotonów docieraja,cych do fotorecep- torów, w´sród nich zwe,˙zanie i rozszerzanie ´zrenicy oka, które mo˙zna przyrówna´c do działania przesłony aparatu fotograficznego. Najnowsze badania pokazuja,, i˙z analogiczna, role, na poziomie molekularnym pełnia, luteina i zeaksantyna, barwniki karotenoidowe zlokalizowane w plamce ˙zółtej siatkówki oka.

Mechanizm ten, okre´slony przez badaczy mianem ˙zaluzji molekularnych blokuje przechodzenie fo- tonów do fotoreceptorów przy silnym ´swietle, ułatwiaja,c ich transmisje, w warunkach niskiego nate,˙zenia promieniowania. Na znaczenie aktywno´sci tego mechanizmu wskazuje fakt, i˙z niedobory barwników plamki ˙zółtej prowadza, do nieodwracalnej utraty wzroku. Podczas wysta,pienia zaprezentowane zostanie funkcjonowanie ˙zaluzji molekularnych w oku człowieka. Przedstawione be,da, równie˙z rekomendacje dotycza,ce diety wpływaja,cej na wysoki poziom barwników plamki ˙zółtej w siatkówce. Korzystanie z tych rekomendacji pomo˙ze słuchaczom zapewni´c sobie sokoli wzrok przez długie lata ˙zycia!

[1] R. Luchowski, W. Grudzi´nski, R. Welc, M.M.M. Pinto, A. Sek, J. Ostrowski, L. Nierzwicki, P. Chodnicki, M. Wieczor, K. Sowi´nski, R. Rejdak, A.G.M. Juenemann, G. Teresi´nski, J. Czub, W.I. Gruszecki, Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye, J. Phys. Chem. B, 125 (2021) 6090-6102.

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XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Plenary

lecture W-01

A brief perspective in high temperature superconductivity

Józef Spałek

Institute of Theoretical Physics, Jagiellonian University, 30-348 Kraków

High temperature superconductivity encompasses the cuprates, nickelates, iron compounds, and the hydrogen-sulphur compounds. The first three groups of compounds involve in the pairing electrons, which are strongly to moderately correlated [1], whereas in the last class of systems specific phonon excitations, connected to hydrogen bonding, play a crucial role [2].

In this overview I concentrate first on the (semi)quantitative theory of high-Tc superconductivity in the cuprates based on our original variational approach beyond the renormalized mean field theory. Selected equilibrium and dynamic-excitation properties are analyzed briefly. General questions regarding the pseudogap and two-dimensional character of those systems are raised.

In the second part of the talk selected basic physical properties of the nicklates [3] and hydrogen-sulphur systems [4] are briefly characterized. At the end, some basic questions such as reduced system dimen- sionality, nonstandard chemical bonding, and the Mottness, are discussed.

Acknowledgments The work is funded by Grants: OPUS UMO-2018/29/ST3/02646 and UMO-2021/41/B/ST3/04070 from Narodowe Centrum Nauki (NCN).

References

[1] J. Spałek, M. Fidrysiak, M. Zegodnik, and A. Biborski, Phys. Rep. 959, 1-117 (2022).

[2] I. Errea et al., Nature 532, 81 (2016).

[3] Y. Nomura and R. Arita, Rep. Prog. Phys. 85, 052501 (2022).

[4] A. P. Drozdov et al., Nature 569, 528 (2019).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-02

Pseudogap in underdoped cuprate seen in longitudinal magnetoresistance

Artur Malinowski, Valeriy L. Bezusyy, and Piotr Nowicki

Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland

We present the results of in-plane magnetotransport study of slightly underdoped cuprate La1.85Sr0.15CuO4

(LSCO15) with Ni impurity. Increasing Ni content y causes a sharp drop in longitudinal magnetoresis- tance (LMR), detected in LSCO15, to broaden and move towards higher temperatures. Temperature TmLMR(y) of this local maximum in LMR coincides with temperature Tdev(y), below which ideal resis- tivity from the parallel-resistor model deviates from its T²-dependence and not from the T -linear one. A direct comparison with the hole doping evolution of pseudogap (PG) in La_2xSrxCuO₄, possible through the mobile-carrier concentration extracted from the thermopower measurements, allows to equate both characteristic temperatures TmLMR ' T_dev with PG opening temperature T^?. The rate of PG closing by magnetic field parallel to the CuO2 plane, in measurements up to 9 T, is consistent with the spin- paramagnetic effect and yields PG closing field Bpc close to the second critical field Bc2 predicted for superconducting gap with the help of Werthamerâ ˘A ¸SHelfandâ ˘A ¸SHohenberg theory.

The low-field data allow also to predict that Bc2 in T=0K limit decreases in the system from 83 T to 56 T when y increases from 0 to 0.035. Examination of the spin part in magnetic susceptibility reveals that increased Stoner factor can be partially responsible for the enhancement of the Pauli paramagnetic effect. Increasing Ni content separates the relevant Zeeman energy scales, gµBB_c2 and gµBBpc (g=2), both decreasing with increasing y, from the pseudogap thermal energy scale kBT^?, equal to them for y= 0 but increasing with increasing y.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-03

Cuprates - the perspective of electronic transport

Wojciech Tabi´s^1,2

1AGH University of Science and Technonlogy,

Faculty of Physics and Applied Computer Science, 30-059 Kraków, Poland

2Institute of Solid State Physics, TU Wien, 1040 Vienna, Austria

Despite immense efforts, the cuprate Fermi surface (FS) has been unambiguously determined in only two distinct, low-temperature regions of the phase diagram: a large hole-like FS at high and, at moderate dop- ing, a small electron-like pocket associated with charge-density-wave (CDW) driven FS reconstruction stabilized by high magnetic fields. I will present systematic resistivity, magnetotransport, and Hall effect measurements for a number of cuprates in a wide temperature and charge-carrier range. Our electronic transport results indicate a significant change of the carrier density upon crossing from the overdoped to underdoped regime. [1–3] This change corresponds to the localization of one hole per primitive unit cell CuO₂. Furthermore, the detailed observation of the evolution of the transport coefficients across the cuprate phase diagram indicate that the decrease of the density of states at the FS, reflects the formation of disconnected Fermi-arcs, but is not a consequence of a true reconstruction of the FS driven by a phase transition. [4] The transport properties directly steam from the Fermi-arc evolution with doping and tem- perature, where arcs states remain essentially unchanged, and from the scattering rate that is dominated by the Umklapp process. Finally, I will present the arguments for a phase transition associated with the enhancement of the CDW order by high magnetic fields and low temperatures in the underdoped regime of the cuprate phase diagram. [4]

References

[1] N. Bariši´c et al., New J. Phys. 21 (2019) 113007 [2] S. Badoux et al., Nature 532 (2016) 210

[3] C. Putzke et al., Nature Phys. 17 (2021) 826 [4] W. Tabi´s et al., arXiv:2106.07457 (2021)

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-04

Two-band superconductivity in electron-irradiated PrOs₄Sb₁₂ and CeCu₂Si₂studied by local magnetization measurements

J. Juraszek¹, Ł. Bochenek¹, M. Ko´nczykowski², D.G. Franco³, S. Seiro³, Ch. Geibel³, T. Cichorek¹

1Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, Poland

2Laboratoire des Solides Irradiés, CEA/DRF/lRAMIS, École Polytechnique, CNRS, Institut Polytechnique de Paris, Palaiseau, France

3Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany

The heavy-fermion and multiband superconductor PrOs₄Sb₁₂with broken time-reversal symmetry, spon- taneously developing on passing through the critical temperature Tc' 1.85 K, is a leading candidate to display chiral superconductivity. Based on measurements of the temperature dependence of the lower critical field H_c1(T ), we have recently found evidence for the order parameters composed of a sign- changing smaller gap and a large isotropic s-wave gap [1].

To develop a detailed understanding of multicomponent superconductivity in PrOs₄Sb₁₂, we have ex- tended measurements of Hc1(T ) down to temperatures as low as 7 mK utilizing a 2DEG Hall magnetom- etry. We observe a sudden increase in Hc1(T ) deep in the superconducting state, indicative of a rare case of two nearly decoupled bands. Furthermore, a non-saturating and concave behaviour of H_c1(T ) below about 0.45 K clearly points at a sign-changing symmetry of the smaller gap. Equally remarkable is a high sensitivity of this characteristic to electron irradiation. Indeed, a concentration of artificial atomic defects as small as a few 0.1% results in both a saturation of H_c1(T ) at T < 0.15 K and a strong suppres- sion of the anomalous enhancement below ' 0.25Tc, consistent with a destruction of an unconventional order parameter due to the smaller gap. Possible symmetries of the smaller gap as well as results of a comparative study on the two-band isotropic s-wave homologue LaRu₄As₁₂ (Tc= 10.4 K) [2, 3] will be discussed in the context of a putative chiral spin-triplet pairing state in PrOs4Sb12.

In addition, we report in- and out-of-plane H_c1(T ) dependencies of the prototypical heavy-fermion ma- terial CeCu2Si2(Tc' 0.58 K, S-type), for which two-band and fully gapped superconductivity has been recently observed. For both [100] and [001] directions, we found clear anomalies (at ' 0.36Tc and ' 0.39Tc, respectively) followed by moderate enhancements. Unlike to PrOs₄Sb₁₂, however, both H_c1^a(T ) and H_c1^c (T ) curves saturate in the limit T = 0, being more consistent with an s±-wave scenario than a d_xy+ d_x²_−y² band-mixing paring model. Besides, the effect of electron-irradiation on the anomalous enhancement of H_c1(T ) at T  Tcwill be shown.

References

[1] J. Juraszek et al., Phys. Rev. Lett. 124 (2020) 027001.

[2] J. Klotz et al., Phys. Rev. B 100 (2019) 205106.

[3] Y. Mizukami et al., Phys. Rev. Res. 2 (2020) 043428.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-05

Magnetic phase transition in TbAl₃(BO₃)₄below 700 mK - quantum and classical features

T. Zajarniuk¹, A. Szewczyk¹, P. Wi´sniewski², M. U. Gutowska¹, R. Pu´zniak¹, H. Szymczak¹, I. Gudim³, V. A. Bedarev⁴, P. Tomczak⁵

1Institute of Physics, Polish Academy of Sciences, Warsaw, Poland

2Inst. of Low Temperature and Structure Research, PAS, Wrocław, Poland

3Kirensky Institute of Physics, SB RAS, Krasnoyarsk, Russia

4B. Verkin Inst. for Low Temp. Physics and Engineering, Kharkiv, Ukraine

5Faculty of Physics, Adam Mickiewicz University, Poznan, Poland

Specific heat, CB, and magnetization, M, of a TbAl3(BO3)4single crystal were studied for temperatures, T, from 50 mK to 300 K, with emphasis on the T < 1 K range, where a phase transition was found at 0.68 K. Nuclear, lattice and critical (C_cr) contributions to CBwere separated. We found that: (i) the phase transition shifts to lower T with increase in magnetic field B||, parallel to the easy magnetization axis, (ii) Ccr∼ T^y0, and (iii) the Grüneisen ratio, Γ, defined as:

Γ = −1 T

(∂ S/∂ B)T

(∂ S/∂ T )B

= −(∂ M/∂ T )B

CB(T ) = 1 T

∂ T

∂ B



S

(1) (S is entropy) diverges as a function of B||for B||approaching a critical value of 0.6 T. The dependences of both C_cr and Γ on T (especially scaling of the latter for B_||≥ 0.30 T), as well as the dependence of Γ on B_|| are characteristic of the systems, in which the classical phase transition line is influenced by quantum fluctuations, QF, and ends at a quantum critical point. By analyzing the y0 and Γ values, we assessed the dynamical critical exponent z to be 0.82 ≤ z ≤ 0.96. Based on these results, we suppose that QF dominate the behavior of the system and destroy the long range order, i.e., we suppose the transition to have a quantum character.

The interpretation that this is the transition to the ferromagnetic ordering of Tb³⁺ magnetic moments is the most natural, intuitive, and supported by the studies of M. However, such a classical transition should be smeared and shifted to higher T by B_||, while we observe the opposite effect. Such effect was observed in systems, in which not only the exchange interactions but also magnetic dipolar interactions were essential. However, the possibility, that the transition is related to any other kind of ordering, e.g., a multipolar ordering, can not be ruled out a priori.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-06

Superconductivity in Os-based Laves compounds

Karolina Górnicka, Michał J. Winiarski, Tomasz Klimczuk

Faculty of Applied Physics and Mathematics, Gda´nsk University of Technology, Narutowicza 11/12, 80-952 Gda´nsk, Poland

Laves phase compounds belong to the class of Frank - Kasper phases showing topologically close-packed structures. They are categorized primarily into three parent members: the C14 hexagonal MgZn₂ - type (P63/mmc), the C15 cubic MgCu2 - type (Fd − 3m) and the C36 hexagonal MgNi2 - type structures (P63/mmc). The discussion on the special properties of Laves phases started in the 1920s and 1930s.

Laves’s work gave the first valuable insight into the characteristics of this class of materials.Especially in the last 30 years AB2- type Laves phase compounds have been a subject of particular interest in solid state physics due to the variety of their physical properties. Today, over a thousand binary and ternary Laves phase intermetallics have been synthesized and characterized, of which about 60% contain a rare earth metal atom.

Motivated by describing the Os-based Laves superconductors, we synthesized and tested ROs₂materials (R = Lu, Y, Sc). The bulk nature of the superconducting transitions for LuOs2, YOs2, and ScOs2 is evident from the visible anomalies at Tc = 3.47 K, 4.55, and 5.36 K, respectively. The heat capacity experiment revealed that all compounds are moderately coupled type-II superconductors.

Acknowledgments The work at GUT was supported by the National Science Center (Poland), project No.2019/33/N/ST5/01496.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-07

Hubbard subbands in the infinite-layer nickelate

Andrzej M. Ole´s^1,2, Tharathep Plienbumrung^3,4, Maria Daghofer^3,4, Michael T. Schmid⁵

1Max Planck Institute for Solid State Research, Stuttgart, Germany

2Institute of Theoretical Physics, Jagiellonian University, Kraków, Poland

3Functional Matter and Quantum Technologies, Univ. Stuttgart, Germany

4Integrated Quantum Science and Technology, Univ. Stuttgart, Germany

55Waseda University, Okubo, Shinjuku, Tokyo, Japan

Starting from an effective two-dimensional (2D) two-band model for infinite layer nickelates [1], con- sisting of bands obtained from d and s–like orbitals, we investigate whether this model can be mapped onto a single-band Hubbard model. With exact diagonalization and the Lanczos algorithm we determine the electron density distribution {nd, ns} in an eight-site 2D cluster. One finds a competition between low-spin and high-spin states in undoped nickelate [2]. Screening of interactions within the s band redis- tributes electrons over the bands and destroys antiferromagnetism. The holes realize doping δ = 1 − nd

in partly filled lower Hubbard band (LHB) of the correlated x²− y² band, and considerable spectral weight is then transferred from the upper Hubbard band (UHB) to the unoccupied part of the LHB (i.e., above the Fermi level). The mechanism of such a spectral weight transfer is well known in a doped Mott insulator [3] and explains why the weight of the LHB increases beyond that expected for the correlated d band at half filling. The largest weight transfer emerges at reduced Coulomb interaction Ud= 4 eV and moderate screening of 50%. The Hubbard bands form in the correlated x²− y²band and the weight transfer occurs only when the strongly correlated band is partly filled.

Acknowledgments T. P. acknowledges Development and Promotion of Science and Technology Tal- ents Project (DPST). A. M. Ole´s is grateful for support via the Alexander von Humboldt Foundation Fellowskip (Humboldt-Forschungspreis).

References

[1] T. Plienbumrung, T. Schmid, et al., Condensed Matter 6, 33 (2021).

[2] T. Plienbumrung, M. Daghofer, A. M. Ole´s, Phys. Rev. B 103, 104513 (2021).

[3] H. Eskes and A. M. Ole´s, Phys. Rev. Lett. 73, 1279-1282 (1994).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-08

Hund excitations in orbital-selective Mott insulators

J. Herbrych¹, M. ´Sroda¹, J. Mravlje², E. Dagotto^3,4

1Wrocław University of Science and Technology, Poland

2Jožef Stefan Institute, Slovenia

3University of Tennessee, Knoxville, USA

4Oak Ridge National Laboratory, USA

Strongly-correlated electron systems are at the heart of many modern condensed matter physics phe- nomena. The celebrated Mott insulators, originating in the strong electron-electron correlations, are still extensively studied in the context of the high-temperature superconductivity of cuprates. On the other hand, the complicated multiorbital Fermi surface of iron-based superconductors can lead to novel phe- nomena not present in "standard" Mott physics. A nontrivial example of the latter is the orbital-selective Mott phase (OSMP), where Mott-localized and itinerant electrons coexist. In this talk, I will show that additional energy scales present in the multiorbital systems, i.e., the Hund interaction, lead to novel bands in the single-particle spectrum of the system. I will primarily discuss that one gets multiple Hund and Hubbard modes instead of the upper- and lower-Hubbard band known from the single-orbital Hubbard model. Finally, I will present the optical conductivity data, which can serve as a simple experimental tool to probe such phenomena.

Acknowledgments This research was supported by the Polish National Agency of Academic Ex- change (NAWA) under contract PPN/PPO/2018/1/00035 and by the National Science Centre (NCN), Poland via project 2019/35/B/ST3/01207.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-09

Non-Abelian Berry phase induced entanglement between qubits in QED cavity

Marcin M. Wysoki´nski, Marcin Płodzie´n, Sarath Prem, Mircea Trif International Research Centre MagTop, Institute of Physics,

Polish Academy of Sciences, Warszawa, Poland

Geometric phases, generated by cyclic evolutions of quantum systems with degenerate groundstate pro- viding qubit basis, offer realization of the non-Abelian statistics. As compared to dynamic gates, non- Abelian geometric control over such a qubit should benefit from tolerance to fluctuations. On the concrete example of dynamically driven hole-spin 3/2 immersed in QED cavity in Ref. [1] we have shown that the interplay between the non-Abelian Berry phases generated by local time-dependent electrical fields and the shared photons allows for fast manipulation, detection, and long-range entanglement of the qubits.

Moreover, we have demonstrated that owing to its geometrical structure, such a scheme is indeed robust against external noises. Additionally, we have confirmed that the found mechanism also applies to quan- tum dot qubits [2] where single gate holonomic operations are executed by cyclic control of the position of confining potential.

Acknowledgments We are supported by the International Centre for Interfacing Magnetism and Su- perconductivity with Topological Matter project, carried out within the International Research Agendas program of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund.

References

[1] M.M. Wysoki´nski, M. Płodzie´n, M. Trif, Phys. Rev B (2021) 104, L041402 [2] S. Prem, M.M. Wysoki´nski, M. Trif, (in prepration)

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-10

Strong-coupling superconductivity of SrIr₂and SrRh₂: Phonon engineering of metallic Ir and Rh

Sylwia Gutowska¹, Karolina Górnicka², Paweł Wójcik¹, Tomasz Klimczuk², Bartłomiej Wiendlocha¹

1Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Aleja Mickiewicza 30, 30-059 Kraków

2Faculty of Applied Physics and Mathematics and Advanced Materials Centre, Gda´nsk University of Technology, ul. Narutowicza 11, Gda´nsk

The two title compounds, SrIr2 and SrRh2, are so-called Laves phases which superconduct with Tc = 6.1 K and 5.4 K, respectively. Their crystal structure is closely related to the underlying monoatomic f cc phases of elemental M = Ir and Rh, with the tetrahedrons of M as the main building blocks. Further on, we see similarities between SrM2and elemental M on the microscopic level. The electronic structure of the Laves phase is roughly speaking the charge-doped electronic structure of the elemental metal, as Sr is a charge reservoir. Also the phonon spectra show similarities between those two systems. In spite of these similarities, both groups of materials have strikingly different superconducting properties, as Ir and Rh are poorly-superconducting materials with Tcs of 0.3 K and 0.003 K, respectively. The aim of our work was to explain how the insertion of Sr into the Ir/Rh network changes the poorly superconducting metals into strongly coupled superconductors, as small electron doping effect is not sufficient to explain that. What we have found may be labeled as phonon engineering as the modifications in phonon spec- tra occurred to be the key ingredient in making the Laves phases the strongly coupled superconductors.

Eventhough Sr has a smaller atomic mass than Ir or Rh, its presence in the structure influences prop- agation of phonons in the network of M tetrahedrons, leading to a substantial lowering of frequencies of selected phonon branches, enhancing the electron-phonon interaction and multiplying Tc. Moreover, this mechanism seems to be quite general and explains strong-coupled superconductivity of other related Laves phases.

Acknowledgments Work supported by the National Science Centre (Poland), projects 2017/26/E/ST3/00119, 2017/26/D/ST3/00109 and UMO-2019/33/N/ST5/01496.

S.G. was partly supported by the EU Project POWR.03.02.00-00-I004/16.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-11

Ternary superhydrides: in search of low-pressure high-temperature superconductor

Artur P. Durajski

Institute of Physics, Cze,stochowa University of Technology, Ave. Armii Krajowej 19, 42-200 Cze,stochowa, Poland

Motivated by the recent experimental discovery of high-temperature carbonaceous sulfur hydride (C- S-H) [1], we have systematically explored the superconductivity of a carbonaceous lanthanum hydride (C-La-H) ternary compound in the pressure range of 50-250 GPa. Based on first-principles calculations and strong-coupling Migdal-Eliashberg theory, we find that a hitherto unreported LaC2H8ternary system is dynamically and thermally stable above 70 GPa in a clathrate structure with space group Fm3m and exhibits a superconducting critical temperature in the range of 69-140 K [2]. The obtained results have important implications for tuning pressure and Tcthrough appropriate doping and in the future, they may contribute to the discovery of superconducting materials at ambient conditions.

References

[1] E. Snider, N. Dasenbrock-Gammon, R. McBride, M. Debessai, H. Vindana, K. Vencatasamy, K.V. Lawler, A. Salamat and R. P. Dias, Nature, 586, 373-377 (2020).

[2] A. P. Durajski, R. Szcze,´sniak, Phys. Chem. Chem. Phys., 23, 25070 (2021).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-12

Theory of superconductivity with local electron pairing: history and perspectives

Tomasz Kostyrko

Faculty of Physics, Institute of Spintronics and Quantum Information, A. Mickiewicz University, ul. Uniwersytetu Pozna´nskiego 2, 61-614 Pozna´n

The theory of superconductivity with local electron pairing [1, 2] was founded chiefly by the Polish au- thors: Roman Micnas and Stanisław Robaszkiewicz and their co-workers, beginning since early 1980’.

The approach is based on the assumption that the basic properties of the superconductors can be explained using an effective short ranged dispersionless attraction between electrons. Although the first works in this field appeared yet before discovery of superconductivity in cuprate oxides, the original motivation for its development was to study the properties of a hypothetical high-temperature superconductors with electronic attraction due to the coupling of electrons to some high energy bosonic excitations, e.g. ex- citons or optical phonons. The generic models used in the theory are: the Hubbard Hamiltonian with a negative on-site or intersite attraction, the periodic Anderson model, and the boson-fermion model.

The theory proved to be useful, e.g. in discussion of the universal properties of unconventional super- conductors as described by so-called Uemura plots, in an analysis of the BCS-Bose crossover, and in an explanation of the pseudogap in the underdoped cuprate superconductors. In a limit of a very strong on-site electron attraction the theory describes superconductors with local electron pairs. In the latter case some accurate, explicit formulas for various superconducting characteristics of the system were ob- tained, which can be used for testing the general theory. In this talk I plan to present a short historical account of the development of the theory, its main advantages and limitations, its present day reception and some recent applications.

References

[1] R. Micnas, J. Ranninger, and S. Robaszkiewicz, Rev. Mod. Phys.62, (1990) 113.

[2] R. Micnas and S. Robaszkiewicz, Cond. Matter Phys.,1 (1998) 89.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-13

Chwila wspomnie ´n po 36 latach

Andrzej Szytuła

Instytut Fizyki Uniwersytetu Jagiello´nskiego, Kraków

W bie˙za,cym roku mija 36 lat od odkrycia zjawiska wysokotemperaturowego nadprzewodnictwa. Pragne, przypomnie´c okoliczno´sci tego odkrycia w szczególno´sci w Polsce, które doprowadziły do konsoli- dacji i rozwoju ´srodowiska prowadza,cego badania w tej tematyce. Efektem tego było powstanie cyk- licznego Krajowego Sympozjum ”Nadprzewodnictwo Wysokotemperaturowe”. W tym roku jest to ju˙z 20 spotkanie. Warto przypomnie´c te ”gora,ce dni”. ”Pie,kno nauki na tym polega, ˙ze tyle jest zjawisk nieprzewidywalnych” (Paul Chu, Ching-wu).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Plenary

lecture W-14

Interplay of various order parameters and disorder in iron chalcogenides

Marta Z. Cieplak

Institute of Physics, Polish Academy of Sciences, Warsaw, Poland

Since the discovery of iron-based superconductors over a decade ago large efforts are directed towards uncovering the primary order parameter determining the properties of these materials. However, the abundance of various low-temperature phases observed experimentally suggests that there may be no single order parameter, instead, many degrees of freedom, including nematic, spin, charge, or orbital degrees of freedom, are strongly intertwined. In addition, these materials are prone to various forms of disorder, which influences the nature of the ground state.

In this talk, I will summarize several years of our studies of iron chalcogenide system, FeTe1−xSex, in which the disorder is introduced intentionally by two different methods, substitution of transition metal element, Ni, into Fe-site, and by changing the crystallization rate during the crystal growth. This last method introduces either excess, or deficiency of the Fe, what affects both the crystal quality, and superconductivity, with the surprising result that the superconductivity is enhanced in crystals of inferior crystallographic properties [1]. Over the years, we have used various experimental probes to understand this behavior, including transport [2], photoemission [3], and, most recently, magnetization and angular magnetoresistance experiments. I will combine the results of these experiments and discuss how the interplay of nematicity, spin fluctuations, and disorder-induced doping affects ground state properties of this system.

Acknowledgments The work done in collaboration with I. Zajcewa, K.M. Kosyl, A. Lynnyk, and D. J.

Gawryluk. Supported by Polish NSC grant 2014/15/B/ST3/03889. The research was partially performed in the laboratory co-financed by the ERDF Project NanoFun POIG.02.02.00-00-025/09.

References

[1] D. J. Gawryluk, et al., Supercond. Sci. Technol. 24, 065011 (2011).

[2] V. L. Bezusyy et al., Phys. Rev. B 91, 100502(R) (2015).

[3] M. Rosmus et al., Supercond. Sci. Technol. 32, 105009 (2019).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-15

Superconductivity in the Heusler-type intermetallic compounds

T. Klimczuk¹, K. Górnicka¹, G. Kuderowicz², M.J. Winiarski¹, K. Kutorasi´nski¹, B. Wiendlocha²

1Faculty of Applied Physics and Mathematics and Advanced Materials Centre, Gda´nsk University of Technology, Narutowicza 11/12, 80-233 Gda´nsk, Poland

2Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Aleja Mickiewicza 30, 30-059 Kraków, Poland

Although discovered more than a century ago, the Heusler material classes remain an exciting and active research area. Interestingly, there are more than 1000 reported compounds in this family, and only 35 of them are superconductors.

In this lecture, recently reported Heusler-type superconductors: MgPd2Sb [1], LiPd2Ge [2], LiPd2Si [3], LiGa₂Rh [4] and LiGa₂Ir [5] will be presented.

MgPd₂Sb is the first Mg-based a Heusler-type compound in which superconductivity is revealed. The number of valence electrons for MgPd₂Sb is VEC = 27 and falls exactly at the maximum of the proposed Tc vs. VEC [6]. For LiPd2Ge and LiPd2Si the number of valence electrons is 25, and for the other two Li-based superconductors (LiGa₂Rh and LiGa₂Ir) VEC = 16. While the last two materials are type-II superconductors, LiPd₂Ge is a rare case of an intermetallic compound for which type-I superconductivity is observed. Theoretical calculations of the phonon structure indicate the possibility of the so-called soft modes in LiPd₂Ge, which lead to the amplification of the electron-phonon coupling and consequently to the occurrence of superconductivity in this family.

Acknowledgments This work is supported by the two National Science Centre (Poland) projects:

2017/27/B/ST5/03044 (PG) and 2017/26/E/ST3/00119 (AGH).

References

[1] M.J. Winiarski, et al., Phys. Rev. B 103, 214501 (2021).

[2] K. Górnicka, et al., Phys. Rev. B 102, 024507 (2020).

[3] K. Górnicka, in preparation.

[4] E. Carnicom, et al., Chem. Mater. 31, 2164-2173 (2019).

[5] K. Górnicka, et al., Sci. Rep. 11, 16517 (2021).

[6] T. Klimczuk, et al., Phys. Rev. B 85, 174505 (2012).

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-16

Properties of (Nb, Pb, In)/NbP - superconductor/Weyl semimetal junctions G. Grabecki¹, A. D ˛abrowski¹, P. Iwanowski^1,2, A. Hruban¹, B.J. Kowalski¹, N. Olszowska³, J. Kołodziej³, M. Chojnacki¹, K. Dybko^1,2, A. Łusakowski¹,

T. Wojtowicz², T. Wojciechowski^1,2, R. Jakieła¹, A. Wi´sniewski^1,2

1Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland

2International Research Centere MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, PL-02668 Warsaw, Poland

3National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, PL-30392 Kraków, Poland

Recently, an idea of introducing superconductivity in topological materials has been developed owing to the possibility of non-zero momentum Cooper pairing. One of the consequence of the non-zero momen- tum pairing is the possibility of formation of zero-energy modes that are equivalent to Majorana fermions which show potential for practical realization of fault-tolerant topological quantum computation. While there is still a long way to build such quantum computer, one needs to find an optimal material platform for its construction. In particular, introducing nonzero superconducting order parameter into topolog- ical materials by inducing superconductivity through the proximity effect enables to employ presently achievable Weyl semimetals and conventional superconductors.

In our studies of interface transmission, the (001) surface of NbP single crystal was covered by several hundred nm thick metallic layers of either Pb, or Nb, or In. Upon cooling of the devices during which the metals become superconducting, all three types of junctions show conductance increase, pointing out the Andreev reflection as a prevalent contribution to the subgap conductance. In the case of Pb-NbP and Nb-NbP junctions, the absolute value of the conductance is much smaller than that for the bulk crystal, indicating that the transmission occurs through only a small part of the contact area. An opposite situation occurs in In-NbP junction, where we observe very high and narrow peak at zero bias. The conductance at the peak reaches the bulk value indicating that almost whole contact area is transmitting and, additionally, a superconducting proximity phase is formed in the material. We interpret this as a result of indium diffusion into NbP, where the metal atoms penetrate the surface barrier and form very transparent superconductor-Weyl semimetal contact inside. However, further diffusion occurring already at room temperature leads to degradation of the effect, so it is observed only in the pristine structures.

Despite of this, our observation directly demonstrates possibility of inducing superconductivity in Weyl semimetal.

Acknowledgments The research was partially supported by the Foundation for Polish Science through the IRA Program co-financed by the European Union within SGOP.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-17

Chiral molecule mediated proximity effect

Grzegorz Jung^1,2

1Department of Physics, Ben Gurion University of the Negev, 84105 Beer Sheva, Israel

2Institute of Physics, Polish Academy of Sciences, 02-668 Warszawa, Poland

The proximity effect is well understood in the superconductor to normal metal contacts, however, its understanding is quite limited in systems involving organic molecules. In this presentation we discuss the organic molecules mediated proximity effect between classical BCS superconducting thin film and normal metal nanoparticles. For low-temperature superconducting Nb thin films, a peculiar inverse prox- imity effect has been observed in which the critical temperature and the critical current increase upon the attachment of organic molecules topped with gold nanoparticles. Concomitantly, in the tunneling density of states of the gold NPs, depending on the molecule-mediated coupling strength, either zero-bias peaks or the proximity gaps appear. For strong molecular coupling, the proximity gaps are induced in Au NPs.

Chiral molecules are known to exhibit the chiral induced spin selectivity effect appearing, among others, as chiral-induced magnetization and spin-selective transport. The replacement of straight molecules with chiral ones leads to new features in the proximity effect between conventional BCS superconductors and normal metal nanoparticles. Scanning tunneling spectroscopy shows that the singlet-pairing s-wave order parameter of Nb is significantly altered upon adsorption of chiral polyalanine alpha-helix molecules on its surface. The tunneling spectra exhibit zero-bias conductance peaks embedded inside gaps or gap-like features, suggesting the emergence of unconventional triplet-pairing components with either d-wave or p-wave symmetry at the Nb organic-molecules interface, as corroborated by simulations. These results may open a way for realizing simple superconducting spintronics devices.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Invited

lecture W-18

Electronic structure of the heavy fermion superconductor Ce₃PdIn₁₁ with two inequivalent crystallographic positions of Ce atoms Paweł Starowicz¹, Rafał Kurleto^1,2, Laurent Nicolaï³, Jan Minár³, Marcin Rosmus^1,4,

Łukasz Walczak⁵, Antonio Tejeda⁶, Daniel Gnida⁷, Dariusz Kaczorowski⁷

1Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland

2Department of Physics and Center for Experiments on Quantum Materials, University of Colorado, Boulder, Colorado 80309, USA

3New Technologies-Research Center, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic

4Solaris National Synchrotron Radiation Center, Jagiellonian University, Czerwone Maki 98, 30-392 Kraków, Poland

5PREVAC sp. z o.o., Raciborska 61, PL-44362 Rogów, Poland

6Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France

7Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422 Wrocław, Poland

We studied the electronic structure of the antiferromagnetic heavy-fermion superconductor Ce3PdIn11by means of angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT). The ARPES measurements were conducted at T = 6 K using photon energy of 122 eV, corresponding to Ce 4d-4f resonance, which enhances the spectral contribution of Ce 4f electrons. The Fermi surface mapped in the experiment appeared quite complex with some branches similar to those observed before in related CeTIn₅ and Ce₂TIn₈ (T = Co, Rh, Ir, Pd) systems. The ARPES spectra reflected strong hybridization between 4f and conduction band electrons which leads to enhanced effective masses of 4f quasiparticles.

Analysis of the spectral width as a function of binding energy revealed features characteristic of Fermi liquid state. The ARPES spectrum related to the f_7/2¹ final state showed an energy splitting of 50 meV, which may originate from crystalline electric field effect.

The DFT calculations made using Korringa-Kohn-Rostoker method allowed to reproduce qualitatively the dispersions and parts of the Fermi surface seen in the experiment. The total Bloch spectral function and its projection on atomic orbitals reflected contributions of different atoms to the valence band. In particular, distinct features were found due to the Ce atoms located at the crystallographic 2g and 1a sites, what implies different hybridization effects related to the two Ce atom sublatices in the Ce3PdIn11

unit cell.

XX-TH CONFERENCE ON SPERCONDUCTIVITY

"New phases, concepts and advances"

Lublin, 22-26 May 2022

Lecture W-19

Badania ˙zelazowo-arsenowych nadprzewodników wysokotemperaturowych z wykorzystaniem promieniowania synchrotronowego

Damian Rybicki

Akademia Górniczo-Hutnicza, al. Mickiewicza 30, 30-059 Kraków

Na seminarium przedstawie, wyniki pomiarów ˙zelazowo-arsenowych nadprzewodników wysokotemper- aturowych z wykorzystaniem promieniowania synchrotronowego (Solaris i Elettra) metodami XANES (X-ray absorption near edge structure) oraz XLD (X-ray linear dichroism). Wyniki pomiarów technika, XLD na krawe,dzi L^3,2Fe w rodzinie zwia,zków Eu(Fe^1xCox)2As2wskazuja, na ró˙zne obsadzenie orbitali dxz and dyz ˙zelaza, co prawdopodobnie wia,˙ze sie, ze zjawiskiem nematyzmu, który jest obserwowany w tych materiałach [1]. Zaprezentuje, równie˙z wyniki pomiarów technika, XANES (na krawe,dziach Fe oraz As) na zwia,zkach dwóch rodzin tzw. 112 i 122, ró˙znia,cych sie, m.in. struktura, krystaliczna,, w funkcji domieszkowania Fe (Ni lub Co).

Acknowledgments Badania były finansowane przez Narodowe Centrum Nauki (grant 2018/30/E/ST3/00377).

References

[1] Damian Rybicki, Marcin Sikora, Joanna Ste,pie´n, Łukasz Gondek, Kamil Goc, Tomasz Stra,czek, Michał Jurczyszyn, Czesław Kapusta, Zbigniew Bukowski, Michał Babij, Marcin Matusiak, Marcin Zaja,c, Physical Review B 102, 195126 (2020)